Method and apparatus for conversion of hydrocarbons with moving bed of solids



y 1950 T P SIMPSONETAL 2,509,019

METHOD AND AI PARATUS FOR CONVERSION OF HYDROCARBONS WITH MOVING BED 0FSOLIDS Original Filed Sept. 21, 1943 2 Sheets-Sheet l 777mm: 1? J/MPJON,

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INVENTORS AGENT 0R ATTORNEY May 23, 1950 T. P. SIMPSON EFAL METHOD ANDAPPARATUS FOR CONVERSION OF HYDROCARBONS WITH MOVING BED OF SOLIDSOriginal Filed Sept. 21,

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aydkkq 6km AGENT ORATTORNEY I) Patented May 23, 1950 METHOD ANDAPPARATUS FOR CONVER- SION F HYDROCARBONS WITH MOVING BED OF SOLIDSThomas P. Simpson and Frederick E. Bay, Woodbury, and Russell Lee,Wenonah, N. J., assignors to Socony-Vacuum Oil Company, Incorporated, acorporation of New York Original application September 21, 1943, SerialNo. 503,188, now Patent No. 2,439,348, dated April 6, 1948. Dividedandthis application November 22, 1946, Serial No. 711,754 i Claims. 1

1 This application is a true division of application Serial Number503,188, filed in the United States Patent Oflice on September 21, 1943,and which issued as Patent No. 2,439,348 on April 6,

As is well known, hydrocarbons may be converted by contacting them atappropriate conditions with adsorptive contact masses. Such a process isthe catalytic vapor phase cracking of gas oil to gasoline in thepresence of particleform contact masses of the general nature of clays.For example, gas oil vapors at temperatures in the neighborhood of 850F., in the presence of such a contact mass, may be cracked to yieldaround 40% by volume of gasoline, a few per cent of permanent gases, anda small amount of coke which is deposited upon the contact mass, theremainder of the charge being largely unaffected and reappearing as agas oil of a nature substantially similar to that which was charged.

The deposit of coke reduces the activity of the contact mass, andperiodic regeneration is required. Many installations hold the contactmass in place and effect regeneration in situ; More recently, there havebeen developed processes in which the particle-form contact mass flowsin a stream through a zone where it is contacted with hydrocarbons and areaction is continuously carried out, and then through a zone in whichregeneration is continuously carried out. This invention has to do withprocesses of this latter synthetic associations of alumina and silicaapproximating clays, similar adsorptive synthetic materials such as gelsof alumina and/or silica, and co-precipitated gels of these and othermaterials, any of which may or may not have added material such asmetallic oxide, acids, etc., incorporated in or carried in the basecontact mass for special purposes in connection with the contemplatedreaction.

The reactions which may be carried out are most commonly cracking,reforming and similar operations, but may be alkylation, dealkylation,hydrogenation, dehydrogenation, isomeriaation, polymerization,oxidation, and the like.

A very efiicient moving contact mass type of catalytic conversionutilizes the contact mass in the form of a moving, compact bed. In thisoperation, the more usual procedure at present is to flow the reactantcountercurrent to the downflexibility of operation.

wardly moving contact mass. In such countercurrent flow, it is desirableto remain below certain limiting flow rates with regard to the reactant,both to avoid uneven flow through the bed,

and to avoid actual disruption of the bed, particularly at reactantdisengaging surfaces. However, this upper limit of reactant velocitywithin the bed imposes a limiting throughput or space velocity ofreactant which is a needless bar to This invention has for its objectthe provision of a process for the conversion of hydrocarbons in thepresence of a movingparticle-form solid contact mass material in whichthe fluid reactants flow concurrently with the contact mass materialunder such proportioning and control as to effect proper and efli'cientutilization of the contactmass material.

The operation contemplated may be understood more readily fromconsideration of the drawings attached to this specification, Figure 1of which showsin' diagram form a single stage of a reactor operated inthe fashion under discussion. Thi may represent either a regenerat onzone or a reaction zone, since the considerations of fluid reactantvelocity, pressure drop, and the like are the same for both; or it mayrepresent any one of the stages in either a multistage reactor or amulti-stage regenerator.

The other figures of the drawings are Figure 2, a diagram used inexplanation, and Figures 3, 4, 5. 6. '7, and 8 which are utilized toshow possible modifications of structure. All of these drawings arehighly diagrammatic in form.

Turning to Figure 1 of the drawings, there is shown a shell I definingand enclosing a reaction space 2. in which there is maintained a movingcompact column of particle-form contact mass material 3, sup liedthrough pipe 4 and removed through pipe 5. The'contact mass materialmoves downwardly as indicated by arrow 6. Fluid reactant is admitted tothe reactor by pipe 1 into the free space above the surface of thecontact mass column. Near the bottom of the contact masscolumn' thereare a number of inverted troughs 8, 9, I0 extending transversely of thecolumn in a direction perpendicular to the section plane of the drawing.Each trough 8, 9, Ill connects through orifices H with a reactionproduct outlet manifold I2, l3, l4. Fluid reactant entering through pipe1 passes downwardly through the contact mass column and into collectortroughs 8, 9, I0. i

Operation in this fashion has several advantages. First it permits theuse of any desirable space velocity of fluid reactant, since there isavailable not only the normal capabilities arising from vari'ationofreactant flow without change of depth of bed throughout a range widerthan possible with countercurreht flow, but also the possibility ofready variation of bed depth.

Most interesting, however. is thecapability of operation at relativelyhighrates of pressuredrop per foot of linear passage through contactmass.

The ability to use these gives rise to an ability pipe "for contactmass, 3 'the column of contact .inass within the'reactor andtis a'singlecollector or distributortrough attached to pipe l2. In the older 'typeof operation, while the contact mass is flowing downwardly, reactantwould be introduced through pipe 12 :into the space under 8, would passout into the contact mass andwould 'beliberated irom the contactmasscolumnafter passing upwardly therethrough into the space above thesurface or the contact mass in the reactor. "The amount of materialwhich could be "flowed in this manner without disruption of the columnof contact mass would be determined by .the pressure drop or converselyby the linear velocity of reactant within contact mass in that "lastportion of the contact mass immediately below the top boundary of thecolumn. In other words, it would be'the pressuredrop or velocity in .theregion indicated by the arrow A. Now, let us assume that with thecontactmass stlll flowing GOWIIWflldlLZWB flow .the reactantsconcurrently with'the contact mass. The limiting rate of now of'r'eactantis determined, .wnen using an open I disengaging surface, thatis,'one wherein the contact mass assumes its own surlace and is notconfined by a screen or the like, by the pressure drop or conversely bythe velocity in the last portion of the .path of the reactant within thecontact mass, that point, for example, indicated by the arrow B. Fromthis, it may readily be seen that when the area of the disengagingsurface under trough 8 is no greater than the area of the disengagingsurface to which arrow A leads, then, no more reactant may be flowedconcurrently than may befiowed countercurrently, since thecharacteristics of fiow at the point where reactant flow may disrupt the.contact mass bodyare substantially the same. If the area under trough 8is substantially less than the upper surface of the contact mass column,substantlally less reactant may be flowed concurrently thancountercurrent- .ly, otherwise the disengaging surface to which arrow Bpoints would be disrup'ted by turbulence =or boiling and byan ctualcarrying away of particles with reactants. Consequently, in order totake advantage of the possibilities of high .throughputs, available withconcurrent flow, while still using unrestrained or unscreened dis-.engaging surface, arrangements must be made whereby the totaldisengagingsurface area is'substantially greater than thecross-sectional area .of the column of solid contact mass material ireactor. p 7

Returning to Figure 1, it will .be noted that such arrangements havebeen made in that there have been provided several's'eries of collectortroughs, via, 8, 9, and H3 under which total disengaging surface area issubstantially in excess of the crosssectional area of the contact masscolumn. Each of the collector troughs in each of the several levels'is'manifolded to provide a separate reactant collector pipe l2, l3, M foreach level, these collector pipes being combined into a single fluidreactant outlet 15. Another feature here presents itself for attention.Should we attempt to operatea multi level collector with no morestructure than has been discussed, it will be obvious that an attemptwill b'e made by the reactants to pass 'preferentially into thecollector troughs ID in the upper level, the preference decreasing asthe reactant proceeds down through the several collector trough levels.In order to avoid this, a series of valves l6, l7, 18 are installed oneach of the several levelmanifolds asshown. These valves are then soadjusted as 'to secure even flow through all of the several levels. Byevenflow, :we dovnot mean flow equalin amount, but rather such flow inthe collector troughs of each level as will give likedisengagingconditions below each trough. In practice, .we have foundthat if the .proportioning of flow issucl'l that the flow in all levelsabove the bottommostis about equal, and

the flow of any one of such levels is approximately -85% .ofthatafiordedat the bottommost level, substantially equal conditions ofdisengagement will occur. This'desirable condition may be obtainedinseveral ways. It maybe obtained'by a series of throttling valves01123111 lines, or .the valve [6 may be dispensed with and ll.andal8-adjusted to balance the reactant oiftake at such 'levels against.the free -offtake from the .bottommost .level or the job may be donemore orless permanently by the establishment of orifices or similar flowresistance devices of propersize in ltheseveral'lines.

Figures 3 to 8, inclusive, are concerned with modifications ofstructure, with optional .constructions which may be used for the samepurpose as that shown in Figure 1. For example, in Figure 3, thereactorshelll, enclosing the contact mass column .3, may be enlarged incrosssection near its base as at 9, to afford room for-a single level ofcollector troughs 20 whose total area is sufiiciently great to providefor the maximumdesign reactant flow.

In Figure 4, a very simple construction'is shown which affords adisengagingsurface substantially equal to the cross-sectional area ofthe column. In Figure 4, l is the reactant shell and 3, the contact masscolumn; near the bottom of the shell there is provided a partition plate-2i,.from which there depends a plurality of contact mass flow pipes 22.These pipes extend for some little dlstance below plate 2| before theircontents are discharged into the bottom portion of the reactor. In thiscase, the disengaging surface is the surface designated by the arrow C,the reactants being released from the solid at this surface to becollected in space-23 andremoved through outlet pipe 24.

Figure 5 is a cross section of the structure of Figure 4, taken at thelevel indicated showing how the various pipes 22 must be substantiallyuniformly distributed with respect to cross section of the reactorcolumn. The device of Figure l, alone, does not, in itself, offer anyparticular augmentation of disengaging surface area above thecross-sectionalarea of the column. For de- T asoaoio signs where aconsiderable increase is desired, the structure shown in Figure 4 maybeutilized in a multiple level design, as indicated in Figure 6, whereinagain i is a reactor shell, 3 the contact mass column and 25, 26, and2'! are a series of plates with dependent pipes, of the same nature asshown in Figure 4, the whole being arranged in a manner similar to thatof'the collector troughs in Figure 1, each disengaging level beingsimilarly manifolded and valved into a single reactant outlet 28.Another version of reactant disengaging space construction similar inits essentials to that of Figure 4, but particularly preferable inreactors of circular cross section wherein it is sometimes difficult tosecure adequate uniformity of contact mass flow with the plate and pipearrangement of Figure 4, is shown in Figure 7, a cross section of whichis shown in Figure 8, the two of which should be read together forcomplete understanding. this construction, I again represents thereactor shell and 3 the contact mass column, while 29 is a partitionplate pierced by appropriate orifices arranged in an annular concentricfashion, as shown by items 3t, 3t and 32 in Figure 8. Each orifice hasdownwardly extending vertical walls 33, and the whole structure servesagain to estabish a disengaging surface designated by an arrow D below acollector space 34 connected to the reactant outlet 35. This structuremay also be utilized as a multiple level, large area, dlsen gagingstructure in a manner similar to that previously explained in connectionwith Figure 6 and Figure 1.

All of the structures herein discussed have a single feature in common,namely, the provision of a method whereby reactants may be flowedconcurrently with a downwardly moving column of particle-form solidcontact mass under conditions tending to keep that column substantiallycompact and under conditions wherein a disengaging surface is providedwithin and near the bottom of said column which disengaging surface isso proportioned as to permit the passage of large amounts of reactantwithout disruption of the contact mass column and which surface usuallyand preferably is of substantially greater area than the cross-sectionalarea of the contact mass column.

In this specification, the term contact mass column has been utilizedand we have spoken of its cross-sectional area. In practically all casesthe contact mass column will be uniform in cross section throughout itslength. However, in cases difierent designs are utilized in whichconstriction or enlargement of the contact mass column is brought aboutfor some purpose or another, the term cross-sectional area is intendedto mean average cross-sectional area, or in some few specialized cases,the minimum cross-sectional area of the column of contact mass materialexclusive the surface (projected) of the contact mass material boundinga free space into which free space reactant may escape to be separatedfrom the adjacent contact mass material.

We claim:

1. A method for reacting a fluid in contact with a mass of subdividedsolid particles which comprises maintaining" a continuous compact bed ofsaid solid particles under reaction conditions within a confinedreaction zone" from adjacent its upper extremity to its lower extremity,causing the particles of said bed to move downwardly through thereaction zone by continuously supplying particles to the upper portionof the bed and continuously removing particles from the lower portion ofthe bed, supplying a stream of said fluid to he upper portion of thereaction zone and reacting the fluid while passing downwardly through anupper portion of said bed, reversing the direction of flow of said fluidin a horizontally enlarged lower portion of said bed and dischargingfluid from the enlarged portion of said bed at plurality of spaced apartdisengaging surfaces providing a greater total area for gas flow thanthe portion of said bed which is above said enlarged lower portion.

2. A process for the conversion of hydrocarbons which comprisesmaintaining a continuous compact bed of catalyst within a confinedreaction zone from adjacent its upper extremity to its lower extremity,maintaining said bed at conversion conditions, causing the catalyst ofsaid bed to move downwardly through the reaction zone by continuouslysupplying fresh catalyst to the upper portion of the bed andcontinuously removing contaminated cataylst from the lower portion ofthe bed, supplying a stream of hydrocarbons to the upper portion of thereaction zone and passing the same downwardly through an upper portionof said bed, providing a region of enlarged horizontal cross section inthe lower portion of said reaction zone and bed relative to said upperportion of the bed, passing all of said stream of hydrocarbonsdownwardly within the enlarged lower portion of said bed and causing areversal in the direction of flow of the hydroi carbons in the enlargedlower portion of the bed to effect a substantial disengagement of saidhydrocarbons from said bed at a disengaging surface which is positionedentirely substantially below the beginning of said enlarged lowerportion of said bed and which provides a, substantially greatercross-sectional area for gas flow than the horizontal cross-sectionalarea of said bed above said enlarged lower portion of said bed andwithdrawing said hydrocarbons from said disengaging surface of enlargedhorizontal cross section.

3. A process for the conversion of hydrocarbons which comprisesmaintaining a continuous compact bed of catalyst within a confinedreaction zone from adjacent its upper extremity to its lower extremity,maintaining said bed at conversion conditions, causing the catalyst ofsaid bed to move downwardly through the reaction zone by continuouslysupplying fresh catalyst to the upper portion of the bed andcontinuously removing contaminated catalyst from the lower portion ofthe bed, supplying a stream of hydrocarbons to the upper portion of thereaction zone and passing the same downwardly through an upper portionof said bed, providing a region of enlarged horizontal cross section inthe lower portion of said reaction zone and bed relative to said upperportion of the bed, providing a pluraiity of spaced apart collectingzones from which gravity iiow of catalyst is substantially excludedwithin said enlarged region, causing a reversal in the direction of flowof the hydrocarbons in the enlarged portion of the bed at locationsbelow each of said collecting zones and discharging conversion productsupwardly from said locations epoegorc lnsaid enlarged portion ofsald'bed into said collecting zones.

4. That method for the conversion of hydrocarbons in the presence of aparticle-form solid contact mass material which comprises: moving thecontact mass through a confined reaction zone as a compact downwardlyflowing column, passing fluid reactants at reaction conditionslongitudinally through said column and concurrently with the flow ofsaid column, baffling the flow of said column within a horizontallyenlarged portion of said column within the lower section of said columnat a plurality of spaced locations to provide a plurality of spacedapart gas collecting zones from which gravity flow of contact materialis substantially excluded, reversing the direction of flow of the fluidreactants within said enlarged portion of said column at areasimmediately below each of said gas collect- .ing zones to effect asubstantial disengagement of said fluid reactants from .the contactmaterial, passing therfiuid reactants upwardly into said gas collectingzones and withdrawing said fluid re- .actants from said gas collectingzones to a location outside of said reaction zone.

5. .Apparatus .for'hydrocarbon conversion comprising: ,a substantiallyvertical, elongated vessel having along a lower portion of its length avertical section of enlarged horizontal cross-sectional area,,me anstointroduce contact material into the upper section of said vessel tomaintain therein a substantially compact column of downwardly,gravitating contact material particles, means to withdraw contactmaterial from the lower section of said vessel below said enlargedsection, .means to introduce fluid reactants into the upper ,section ofsaid vessel, baiiling along substantially a single horizontal levelwithin said enlarged section of said vessel adapted to definesubstantial gas collecting space from which direct gravity flow-ofcontact materialis excluded, which space is in free communication withthe interior of said enlarged section of said vessel at a single .levelalong substantial horizontal area at the lowerextremity of said space,which area is substantially greater than the horizontal cross-sectionalvarea of said vessel above said enlarged section, and means to withdrawfluid reactants .irom-said space.

,.zont-ally across saidenlarged section of said vessel :along asubstantially single elevational level, said ytroughs providing a totalopen area along their bottomsgreater than that of said vessel above,said enlarged section and means to withdraw :gas from said collectingtroughs.

'7. A method for-reacting a fluid in contact with a m-ass of subdividedsolid particles which com- ,prlses maintaininga continuous compact bedof .said solid particles within a confined reaction :zone from adjacentits upper extremity to its glGWfiI': extremity, causing thelparticles ofsaid bed to move downwardly through the reaction zone by continuouslysupplyingparticles to the upp'erpor- .tion of .the'bed and continuouslyremoving particles from the lower portion of tne bed, supplying a streamofsaid fluid to the upper portion of the reaction zone and reacting thefluid while passing downwardly through an upper portion of said bed,reversing the direction of flow of said fluid in a horizontally enlargedlower portion of said bed and discharging fluid from the enlargedportion of said bed at a plurality of spaced disengaging surfacesproviding a, total cross-sectional area for fluid flow greater than thehorizontal cross-sectional area of said bed above said enlarged lowerportion.

8. That method for contacting gaseous materials withiparticle 'formsolids which comprises:

'moving the particleform solids through a confined contacting zone as asubstantially compact column of downwardly flowing solid particles,passing gaseous material downwardly within said column and concurrentlywith the flow of said solids, battling the flow of said solids within anenlarged portion of said column within the lower section thereof at aplurality of spaced locations to provide a plurality of spaced apart gascollecting zones from which gravity flow of said solid particles issubstantially excluded, reversing the direction or flow of saidgaseousmaterial within said enlarged portion of said column at areasimmediately below each of said gas collecting zones to efiect asubstantial disengagement of said gaseous material from the solids, thetotal of said areas being greater than the horizontal cross-sectionalarea for gas flow in said column above said enlarged portion passing thedisengaged gaseous material into said gas collecting zones andwithdrawing it therefrom to a location outside of said contacting zone.

9. .A method for reacting a fluid in contact with amass of subdividedsolid particles which comprises: maintaining a continuous compact bed ofsaid solid particles under reaction conditions within a confinedreaction zone, causing the ,partieles of said bed to move downwardlythrough the reaction zone by supplying particles to the upper portion ofthe bed and removing particles from the lowerportion of the bed, passingsaid fluid downwardly within said bed in said reaction zone and reactingthe fluid while passing downwardly through said bed, passing all of thefluid into a horizontally enlarged lower portion of said bed to firstefiect a, substantial reduction in the linear rate of flow of the fluidand thereafter .reversing thedirection of flow of the fluid anddisengaging the fiuid from said bed at gas-solid disengagement surface,all of which surface is spaced substantially below the beginning of saidenlarged lower portion of said bed and which provides a substantiallygreater total cross-sectional area for gas flow than the horizontalcross-sectional area of said bed above said enlarged lower portion, andwithdrawing the disengaged fluid.

10. Apparatus for hydrocarbon conversion comprising a, vertical shelldefining a confined reaction space, said shell being of substantiallyconstant horizontal cross-sectional area along the upper and majorportions of its length and having adjacent its lower end a verticalsection of substantially greater horizontal cross-v-sectional area thanthe portion of said shell thereabove, conduit means. to feedparticle-form solid contact material to the upper section of said shellto maintain therein a substantially compact column of downwardly movingsolid particles, means to remove contact material from the "lower H 10section of said shell, a fluid reactant inlet member connecting into theupper section of said shell REFERENCES CITED :geparately f Said conduitmeans f r feeding The following references are of record in the pontactmaterial, and means positioned within file of this Patent: jsaidgnlargedsectiign cxiltrfsaidfshetlll1 adapteiito 5 UNITED STATES PATENTS provi ea isengag g s ace or e separa on 'oi fluid reactant from the contactmaterial col- Number Name Date 664,630 Frasch Dec. 25 1900 nmn, whichdisengaging surface is of greater 1 174 464 Agnew 1 Mar 7 1918 area thansaid upper portion of said shell which Thiele 'i 1943 is of constantcross-sectional area. 10

THOMAS p SIMPSON 23431156 Sheppard May 2, 1944 FREDERICZK E RAY2,394,710 McAfee Feb. 12, 1948 2,400,194 Day et a1 May 14, 1946 RUSSELLLEE.

1. A METHOD FOR REACTING A FLUID IN CONTACT WITH A MASS OF SUBDIVIDEDSOLID PARTICLES WHICH COMPRISES MAINTAINING A CONTINUOUS COMPACT BED OFSAID SOLID PARTICLES UNDER REACTION CONDITIONS WITHIN A CONFINEDREACTION ZONE FROM ADJACENT ITS UPPER EXTREMITY TO ITS LOWER EXTREMITY,CAUSING THE PARTICLES OF SAID BED TO MOVE DOWNWARDLY THROUGH THEREACTION ZONE BY CONTINUOUSLY SUPPLYING PARTICLES TO THE UPPER PORTIONOF THE BED AND CONTINUOUSLY REMOVING PARTICLES FROM THE LOWER PORTION OFTHE BED, SUPPLYING A STREAM OF SAID FLUID TO THE UPPER PORTION OF THEREACTION ZONE AND REACTING THE FLUID WHILE PASSING DOWNWARDLY THROUGH ANUPPER PORTION OF SAID BED, REVERSING THE DIRECTION OF FLOW OF SAID FLUIDIN A HORIZONTALLY ENLARGED POWER PORTION OF SAID BED AND DISCHARGINGFLUID FROM THE ENLARGED PORTION OF SAID BED AT A PLURALITY OF SPACEDAPART DISENGAGING SURFACES PROVIDING A GREATER TOTAL AREA FOR GAS FLOWTHAN THE PROTION OF SAID BED WHICH IS ABOVE SAID ENLARGED LOWER PORTION.